Occurrence of chylous ascites is a rare disorder caused by extravasation of chyle into the peritoneal cavity. The aetiology of chylous ascites is mainly divided into traumatic, including iatrogenic, and atraumatic causes, and this distinction is important for management. The most common causes for atraumatic chylous ascites in adults are malignancy (25%), cirrhosis (16%), mycobacterium infection (15%), and a variety of uncommon causes (23%). A lymphatic anomaly is the most frequent atraumatic cause (84%) in children.Reference Steinemann, Dindo, Clavien and Nocito 1 It is very rare to develop chylous ascites resulting from cardiac lesions, especially in children. In this case report, we present the clinical course of 4-month-old infant who developed chylous ascites while waiting for repair of his cardiac defect.
Case report
A male neonate born at 40 weeks estimated gestational age presented with prenatal echocardiographic diagnosis of left-sided obstructing cardiac lesions. Prostaglandin therapy was initiated after caesarean section. The echocardiogram revealed a hypoplastic aortic arch with ductal-dependent distal circulation, aortic coarctation, mitral valve hypoplasia (z score=−4.1), a mildly hypoplastic left ventricle, and a small (4 mm in diameter) membranous ventricular septal defect. The patient underwent extended end-to-end repair for the aortic coarctation through a left posterolateral thoracotomy. After 6 weeks of his cardiac surgery, because of feeding difficulties and gastroesophageal reflux, he underwent laparoscopic Nissen fundoplication and gastrostomy tube placement. He did not have any significant events after the procedure. His mitral stenosis and ventricular septal defect were followed-up by the paediatric cardiology team. When he was 4.5 months old, he returned to the clinic because of increasing abdominal girth. The combined chest and abdominal X-ray (Fig 1) revealed low lung volumes, cardiomegaly, moderate pulmonary vascular congestion, and a distended abdomen with centralised loops of bowels. An ultrasound of the abdomen revealed a large amount of ascites without any evidence of masses in the liver or peritoneal space. A MRI study was performed to assess the size of the ventricles and to rule out vascular anomalies of the great vessels, such as thrombosis in the portal vein or inferior caval vein (Fig 2). Cardiac catheterisation with general anaesthesia revealed severe pulmonary hypertension with a mean gradient of 8 mmHg across his mitral valve with 0.8:1 shunt across the ventricular septal defect; however, the shunt increased to 4:1 after the administration of pulmonary vasodilators with only a modest increase in the mitral valve gradient. The systolic and mean pulmonary arterial pressures were 93 and 68 mmHg, respectively, whereas the simultaneous systolic and mean systemic pressures were 100 and 84 mmHg, respectively. The mean right atrial pressure was 7 mmHg. The serum level of type B natriuretic peptide was 241.5 pg/ml. Abdominal paracentesis yielded 800 ml of whitish fluid with triglyceride levels of 7705 mg/dl. The patient’s diet was changed to low-fat formula with appropriate diuretics, and there was no re-accumulation of ascites for 2 weeks. After having a multidisciplinary meeting, the decision to proceed with closure of the ventricular septal defect was made. The postoperative course was uneventful. His postoperative pulmonary artery pressure was about 30–40% of the systemic arterial pressure. His nutrition was switched to normal formula 3 weeks after surgery. His mitral stenosis has been followed-up by our cardiac team for more than 14 months, and there has been no sign of abdominal distension or recurrent ascites.
Combined chest and abdominal X-ray. Radiography reveals centralised gas-filled loops of the bowel. No pleural effusion is identified.
MRI of the coronal view. A large volume of ascites is identified.
Discussion
We describe the development of chylous ascites in an infant with ventricular septal defect associated with mitral stenosis and pulmonary hypertension. Chylous ascites have been reported in adults with constrictive pericarditisReference Amasyali, Heper, Akkoc, Yuksel, Kilic and Isik 2 , Reference Riza Altiparmak, Avsar and Yanik 3 or CHD.Reference Cakmak, Yenidünya, Karadağ and Ongen 4 , Reference Ridruejo and Mandó 5 There are very limited reports of children with cardiac lesions in whom chylous ascites present before surgical correction. Ogasawara et alReference Ogasawara, Harada, Tamura, Ito, Kishkurno and Takada 6 reported chylous ascites associated with massive atrioventricular valve regurgitation after performing a Blalock–Taussig shunt in an infant. The ascites decreased after coil embolisation of the ductus arteriosus to minimise excessive pulmonary blood flow. Lin et alReference Lin, Hsu, Wu, Wang, Wang and Chu 7 reported restrictive cardiomyopathy with severe cardiac failure and chylous ascites in a 12-year-old girl after chemotherapy and radiotherapy for intrathoracic rhabdomyosarcoma. The ascites decreased after heart transplantation. Connor et alReference Connor, Angelides and Gibson 8 reported successful resection of localised intestinal lymphangiectasia in 14-year-old girl who underwent a Fontan procedure. The ascites decreased after aggressive resection of the jejunum that was affected with serosal and mucosal lymphangiectasia.
In our case, the patient had severe pulmonary hypertension due to mitral stenosis and ventricular septal defect; however, the mean right atrial pressure was only 7 mmHg under general anaesthesia. The serum level of type B natriuretic peptide was abnormal, although it was not extremely high. The mechanism of chylous ascites in our case is unclear, and we do not know whether our patient had lymphatic anomalies. Chylous ascites in our patient could have been related to several factors. Injury to the thoracic duct after coarctation repair would most likely be associated with the development of a left chylothorax. Theoretically, it is possible that obstruction of the thoracic portion of the thoracic duct due to coarctation repair could promote the later development of chylous ascites; however, the timing of the development of chylous ascites does not correlate with the coarctation repair in our patient. Nissen fundoplication and gastrostomy tube placement could have also contributed to the chylous ascites in our patient; however, the timing does not correlate as the abdominal procedure was performed 3 months before the patient was admitted to the hospital for his chylous ascites.
CHD, particularly when it is right heart failure, might interfere with lymphatic drainage from the abdomen. In our case, the patient had no recurrent ascites after peritoneal drainage, switching to a low-fat diet, and having appropriate diuretics for 2 weeks. The patient has had no recurrent acites after surgical correction of his ventricular septal defect for more than 16 months. We suspect that the presence of mitral stenosis, ventricular septal defect, and the concomitant pulmonary hypertension all conspired to result in the development of abdominal chylous ascites in our patient. The presence of chylous ascites is a rare clinical finding, and can be identified and medically managed before embarking on cardiac surgery.
Acknowledgements
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Conflicts of Interest
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